U.S. patent number 6,880,682 [Application Number 10/466,801] was granted by the patent office on 2005-04-19 for wheel support for vehicles with disk brakes.
This patent grant is currently assigned to Freni Brembo S.p.A.. Invention is credited to Giovanni Gotti, Giovanni Mario Tironi.
United States Patent |
6,880,682 |
Gotti , et al. |
April 19, 2005 |
Wheel support for vehicles with disk brakes
Abstract
A wheel support for providing a connection, rotatable about an
axis (S), between a wheel of a vehicle which can be braked by a
disk brake and the stub axle (6) of the vehicle comprises a bell
(24) suitable for supporting a braking band (25) and a connection
flange (14) for the connection of the vehicle wheel. The bell (24)
and the connection flange (14) are formed integrally, constituting
a single body (2) which can be connected rotatably and releasably
to the stub axle (6) of the vehicle.
Inventors: |
Gotti; Giovanni (Alme',
IT), Tironi; Giovanni Mario (Dalmine, IT) |
Assignee: |
Freni Brembo S.p.A.
(IT)
|
Family
ID: |
11133755 |
Appl.
No.: |
10/466,801 |
Filed: |
July 16, 2003 |
PCT
Filed: |
November 27, 2001 |
PCT No.: |
PCT/IT01/00600 |
371(c)(1),(2),(4) Date: |
July 16, 2003 |
PCT
Pub. No.: |
WO03/04571 |
PCT
Pub. Date: |
June 05, 2003 |
Current U.S.
Class: |
188/218XL;
188/218R; 301/6.7; 301/6.8 |
Current CPC
Class: |
B60B
27/001 (20130101); F16D 65/12 (20130101); F16D
2065/1328 (20130101); F16D 2065/136 (20130101); F16D
2065/1392 (20130101) |
Current International
Class: |
B60B
27/00 (20060101); F16D 65/12 (20060101); B60B
027/02 () |
Field of
Search: |
;188/18A,218XL,218R
;301/6.7,6.8 |
References Cited
[Referenced By]
U.S. Patent Documents
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5507367 |
April 1996 |
Dagh et al. |
5540303 |
July 1996 |
Bodin et al. |
6330937 |
December 2001 |
Dagh et al. |
6446765 |
September 2002 |
Dabertrand et al. |
6467588 |
October 2002 |
Baumgartner et al. |
6564913 |
May 2003 |
Baumgartner et al. |
|
Foreign Patent Documents
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0680836 |
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Nov 1995 |
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EP |
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0783980 |
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Jul 1997 |
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EP |
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0860626 |
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Aug 1998 |
|
EP |
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0860626 |
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Aug 1998 |
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EP |
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2687614 |
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Aug 1993 |
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FR |
|
Primary Examiner: Graham; Matthew C.
Attorney, Agent or Firm: Sofer & Haroun, LLP
Claims
What is claimed:
1. A wheel support for providing a connection, rotatable about an
axis, between a wheel of a vehicle which can be braked by a disk
brake and suspension means of the vehicle, the support comprising a
bell for supporting a braking band and a connection flange for
supporting the vehicle wheel, wherein the bell and the connection
flange are formed integrally, constituting a single body which can
be connected rotatably and releasably to the suspension means by a
releasable connection to a bearing, keyed to said suspension means,
wherein said single body has a substantially tubular portion formed
of a single layer having an inner surface and an outer surface,
where the outer surface forms said bell and the inner surface forms
a seat for the releasable connection to the bearing.
2. A wheel support according to claim 1 in which the seat of the
single body has a depth such that it can at least partially house
the bearing.
3. A wheel support according to claim 1 in which the single body
can be connected releasably to the bearing by means of a plurality
of bolts.
4. A wheel support according to claim 3 in which the single body
comprises a shoulder provided with a flat abutment surface
substantially perpendicular to its axis, the shoulder having a
plurality of through-holes which open in the abutment surface and
are distributed in alignment with internally-threaded holes
provided in a front surface of the bearing, the through-holes being
able to house the plurality of bolts.
5. A wheel support according to claim 4 in which the through-holes
are distributed at intervals around a circle having its centre on
the axis.
6. A wheel support according to claim 1 in which the single body as
a whole is shaped substantially as an axially symmetrical body of
revolution.
7. A wheel support according to claim 1 in which the connection
flange is formed as a substantially annular disk perpendicular to
the axis and has a plurality of holes for housing bolts for the
releasable connection of the wheel.
8. A wheel support according to claim 7 in which the holes house
the bolts with interference.
9. A wheel support according to claim 7 in which the connection
flange is formed on the end of the single body remote from the
seat.
10. A wheel support according to claim 9 in which a substantially
frustoconical connecting region is formed between the connection
flange and the tubular portion.
11. A wheel support according to claim 10 in which the connecting
region has one or more reinforcing ribs.
12. A wheel support according to claim 1 in which the bell region
of the single body is suitable for forming a releasable connection
with the braking band, by means of suitable restraining means.
13. A wheel support according to claim 12 in which the restraining
means comprise a set of teeth formed around the outer circumference
of the bell region suitable for engaging a corresponding set of
teeth formed around the circumference of the central opening of the
braking band in order to achieve a releasable connection between
the single body and the braking band, fixing them for rotation
together about the axis.
14. A wheel support according to claim 13 in which the set of teeth
comprises abutment surfaces which, together with corresponding
abutment surfaces of the set of teeth of the braking band, are in
abutment with one or more restraining rings for preventing axial
sliding of the braking band, at least beyond the limits provided
for by the bell region of the single body.
15. A wheel-support unit according to claim 1 in which the
direction in which the seat of the single body is fitted on the
connecting portion of the bearing coincides substantially with the
axis.
16. A wheel-support unit according to claim 15 in which the seat of
the single body is formed by a substantially cylindrical cavity
having a centring portion, the inside diameter of which corresponds
substantially to the outside diameter of the connecting portion of
the bearing.
17. A wheel-support unit according to claim 16 in which, in the
mounted condition, the bell region is disposed substantially
centrally relative to the axial extent of the bearing.
18. A wheel-support unit comprising a wheel support according to
claim 1 as well as a bearing comprising an inner ring which can be
fixed firmly to the suspension means, and an outer ring associated
rotatably with the inner ring and having a connecting portion to
which the single body can be fixed removably by means of the
plurality of bolts.
19. A wheel-support unit according to claim 18 in which the
connecting portion of the bearing and the seat of the single body
have one or more respective complementary surfaces.
20. A wheel-support unit according to claim 19 in which at least
one of the one or more complementary surfaces achieves a form
coupling between the connecting portion of the bearing and the seat
of the single body when the single body is in the mounted condition
on the bearing.
21. A wheel-support unit according to claim 20 in which the form
coupling can restrain or limit a translational relative movement
between the bearing and the single body in a direction
perpendicular to the axis.
22. A wheel-support unit according to claim 20 or claim 21 in which
the form coupling can restrain and/or limit a rotational relative
movement between the outer ring of the bearing and the single body,
about the axis.
23. A wheel-support unit according to claim 19 in which the
connecting portion of the outer ring comprises a flat front surface
substantially perpendicular to the axis and at least partially
complementary with the abutment surface of the single body, the
front surface having a plurality of holes which open in the front
surface and which are distributed so as to be aligned with the
through-holes provided in the abutment surface of the single body,
the holes being suitable for housing the plurality of bolts.
24. A wheel-support unit according to claim 23 in which the holes
in the front surface of the bearing are internally threaded.
25. A wheel-support unit according to claim 23 or claim 24 in which
the outer ring of the bearing comprises a first substantially
tubular portion and a second substantially tubular portion which is
radially enlarged in comparison with the first tubular portion and
which constitutes the connecting portion.
26. A wheel-support unit according to claim 25 in which the outer
ring comprises a substantially frustoconical transition region
between the first substantially tubular portion and the connecting
portion.
27. A wheel-support unit according to claim 18 in which the bearing
as a whole is shaped as a substantially axially symmetrical body of
revolution.
28. A suspension for vehicles which can be braked by disk brakes,
comprising a wheel-support unit according to claim 18.
29. A bearing suitable for use in a wheel-support unit according to
claim 18.
Description
BACKGROUND OF THE INVENTION
The subject of the present invention is a wheel support for
providing a rotatable connection between a wheel and suspension
means of a vehicle with disk brakes, in particular a heavy vehicle
the wheel flange of which has an outside diameter larger than the
inside diameter of the brake disk used.
In these vehicles, a worn brake disk is generally replaced by
dismantling the wheel-bearing unit.
However, the life of the bearings, which is generally longer than
that of the brake disks, is guaranteed by producers only if the
bearings are never dismantled after their initial assembly.
There is therefore a need to provide braking systems which enable
the brake disk to be replaced without dismantling the bearing
unit.
Solutions have been proposed to fulfil this need but, although they
avoid dismantling the bearing, they have other disadvantages. For
example, there are known disk brakes with braking bands which are
divided into two parts connected to one another releasably to
enable them to be replaced without the need to remove the bearing
unit from the stub axle.
The main disadvantage of this solution is that it is difficult to
ensure precise alignment between the two portions of the braking
band, particularly in an axial direction, because of working
tolerances both of the two parts of the braking band and of the
connection between them.
As a result, the braking surfaces of the two assembled parts do not
define a single braking surface and a stepped discontinuity is
formed along the line of the joint between the two parts of the
braking band. During braking, this step acts as a tool which
removes friction material from the braking surfaces of the pads,
causing rapid and uneven wear of the pads.
A further system of the prior art comprises a bearing, a brake
disk, and a wheel hub, which are independent of one another and
which can be connected by a set of screws, the screws being
inserted in suitable holes provided in the wheel hub and in the
bell of the brake disk and screwed into threaded holes in the outer
ring of the bearing, clamping the bell of the brake disk between
the wheel hub and the bearing, as can be seen in FIG. 2.
Although this solution does not require operation on the bearing
during the replacement of the worn brake disk, it has the
disadvantage of the presence of a fairly large bell which cannot be
reused after the replacement of the disk.
Moreover, in this solution it is necessary to provide for two
centring arrangements, that is, centring of the disk on the bearing
and centring of the wheel hub on the disk bell, requiring at least
four machining operations which are difficult and expensive to
perform.
Furthermore, any use of axially slidable braking bands is rendered
difficult and expensive by the large number of parts to be produced
and assembled.
With regard to the structural behaviour of the systems of the prior
art, they have highly stressed connection members such as the pins
and the bolts which connect the two sectional portions of the brake
disk, as well as the screws for connecting the wheel hub and the
brake-disk bell to the bearing. In particular, during braking, the
latter have to ensure that the joint they form can transmit the
braking torque from the brake-disk bell to the wheel flange.
SUMMARY OF THE INVENTION
The object of the present invention is therefore to propose a wheel
support for vehicles of the type specified above which enables worn
parts of the braking system to be replaced without the need to
perform operations on the bearing, at the same time overcoming the
disadvantages of the prior art.
Within the object of the invention set out above, a further aim is
to provide a wheel support having characteristics such as to stress
the principal connection members uniformly and such as to favour
easy and safe replacement of the brake disk.
These and other objects are achieved by means of a wheel support
according to claim 1.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, a non-limiting
embodiment thereof is described below and is shown in the appended
drawings, in which:
FIG. 1 is a sectioned, perspective view of a wheel-support unit
according to the invention,
FIG. 2 is a view showing a wheel-support unit of the prior art, in
section,
FIG. 3 is an exploded view of the wheel-support unit of FIG. 1,
FIG. 4 is a further exploded view of the wheel-support unit of FIG.
1,
FIG. 5 shows, in section, the wheel-support unit of FIG. 1, after
the removal of a component thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIGS. 1, 3 and 4, a wheel-support unit is
generally indicated 1. The wheel-support unit comprises a
connection flange 14, a bell 24, and a bearing 3, the connection
flange 14 and the bell 24 being formed integrally so as to
constitute a single body 2.
The terms "axial" and "radial" refer below to the axis of rotation
of the individual components (the brake disk, the wheel, the outer
ring of the bearing) when they are mounted on the vehicle. This
rotation axis coincides substantially with the axis S of symmetry
or of axial symmetry of the above-mentioned components, as
specified below. The expressions "interior of the vehicle" and
"exterior of the vehicle", on the other hand, relate to the
orientation of the components when they are mounted on the
vehicle.
The single body 2 has a geometrical shape which is substantially
that of an axially symmetrical body of revolution, comprising a
tubular portion 13 facing towards the interior of the vehicle, as
well as a substantially annular disk-shaped connection flange 14
perpendicular to the axis S. The connection flange 14 is formed on
the end of the single body 2 remote from the tubular portion 13 and
has a plurality of axial through-holes 15 distributed at intervals
around a circle having its centre on the axis S. In known manner,
the axial holes 15 house, with interference, a corresponding
plurality of bolts, known as "studs", provided for the screwing of
a plurality of nuts for the releasable connection of a wheel to the
connection flange 14.
A substantially frustoconical connecting region 16 is formed
between the tubular portion 13 and the connection flange 14 and is
further reinforced by reinforcing ribs 17.
The tubular portion 13 of the single body 2 has an outer surface 18
and an inner surface 19. The inner surface 19 defines a
substantially cylindrical seat 20 which can be fitted, along the
axis S, onto a connecting portion 8 of the bearing 3, in order to
house the connecting portion 8 at least partially but preferably
completely.
As can be seen, for example, from FIG. 1, the seat 20 has a
centring portion of limited depth the inside diameter of which
corresponds substantially to the outside diameter of the connecting
portion 8 of the bearing 3. The total depth of the seat 20 is
greater than the axial length of the connecting portion 8.
The seat 20 is defined, in the axial direction, by a shoulder 21
with a flat abutment surface 22 substantially perpendicular to the
axis S and facing towards the interior of the vehicle. The abutment
surface 22 is at least partially complementary with a front surface
10 of the bearing 3.
The shoulder 21 has a plurality of axial through-holes 23 which
open in the abutment surface 22. The holes 23 are distributed so as
to be aligned with threaded holes 11 in the front surface 10 of the
bearing 3 and can house a plurality of bolts 12 for releasable
connection to the bearing 3.
According to one embodiment, the holes 23 are distributed at
intervals around a circle having its centre on the axis S.
The outer surface of the tubular portion 13 of the single body 2
forms a bell region 24 for the releasable connection of a braking
band 25 to the single body 2, fixing them for rotation together
about the axis S. This releasable connection between the braking
band 25 and the single body 2 takes place in known manner and only
one of the possible connection methods will therefore be described
below.
With reference to FIGS. 3 and 4, a plurality of projections,
parallel to one another and to the axis S, are formed in the bell
region 24 and project substantially radially, forming a set of
teeth 26. The set of teeth 26 has an inner abutment surface 28
facing towards the interior of the vehicle and an outer abutment
surface 30, facing towards the exterior of the vehicle.
The set of teeth 26 of the bell region 24 is intended to engage a
corresponding set of teeth 27 formed around the circumference of
the central opening of the braking band 25 and in turn provided
with internal and external abutment surfaces 29 and 31,
respectively.
According to one embodiment, the bell region 24 for the releasable
connection of the braking band 25 to the single body 2 is disposed
substantially centrally relative to the axial extent of the bearing
3.
The bearing 3 has an inner ring 4 which can be keyed to a stub axle
6 of a vehicle and an outer ring 5, associated rotatably with the
inner ring 4, for example, by means of conical rollers housed in
suitable rolling races between the two rings 4 and 5.
The bearing 3 as a whole is shaped geometrically substantially as
an axially symmetrical body of revolution in which the outer ring 5
has a first tubular portion 7 and a second tubular portion which is
enlarged radially relative to the first portion 7 and which
constitutes the connecting portion 8. A substantially frustoconical
transition region 9 is formed between the first tubular portion 7
and the connecting portion 8.
The connecting portion 8 comprises a flat front surface 10
substantially perpendicular to the axis S. The front surface 10
faces towards the exterior of the vehicle and is at least partially
complementary with the abutment surface 22 of the single body
2.
A plurality of axial holes 11 formed in the front surface 10 are
aligned with the through-holes 23 provided in the abutment surface
22 of the single body 2. The holes 11, which are threaded
internally, are distributed at intervals around a circle having its
centre on the axis S and are provided for the screwing of the
plurality of bolts 12 for the releasable connection of the single
body 2 to the connecting portion 8 of the bearing 3. The radial
enlargement of the connecting portion 8 corresponds substantially
to the space required to house the bolts 12.
According to the preferred embodiment, the bearing 3 is made of
steel, the single body 2 of nodular cast iron, and the braking band
of grey iron.
The operation of the wheel-support unit 1 for vehicles with disk
brakes is described below with reference to FIGS. 4 and 5.
For the initial mounting, the bearing 3, the single body 2, and the
braking band 25 are arranged to be preassembled to form a single
unit which is mounted on the stub axle 6 prior to the mounting of
the caliper.
The bearing 3 is never opened again, throughout its entire life,
guaranteed by the manufacturers.
The wheel is connected to the single body 2, in known manner, by
means of a plurality of nuts which are screwed onto the studs of
the connection flange 14.
During braking, the braking torque is transmitted by the sets of
teeth 26 and 27 from the braking band 25 to the single body 2, and
hence directly to the connection flange 14, without requiring any
further stressing of the bolts 12 which connect the single body 2
to the bearing 3. The braking torque is transmitted from the single
body 2 to the wheel by the joint formed by the wheel-mounting
studs.
A worn braking band is replaced, after the wheel has been removed
from the single body 2 by unscrewing of the screws 34 which
restrain the braking band 25 axially in the bell region 24. The
screws 34 can be reached easily from outside the vehicle, as can be
seen, for example, from FIG. 1 or FIG. 3.
The bolts 12 are then unscrewed from the connecting portion 8,
releasing the single body 2, which can easily be removed by being
slid along the axis S.
Since the central opening in the braking band 25 has a diameter
larger than the outside diameter of the bearing 3, it allows the
worn braking band to be removed and replaced without any operation
on the bearing 3. The individual pieces 33a, 33b of a keeper ring
33 can easily be separated from the tubular portion 13 of the
single body 2 and can be re-used.
After the new braking band 25 has been positioned between the pads
of the caliper by being supported, for example, directly on the
outer ring 5 of the bearing 3, the single body 2 is put in place by
fitting the seat 20 onto the connecting portion 8 of the bearing 3,
along the axis S.
The substantially complementary shapes of the centring portion of
the seat 20 and of the connecting portion 8 advantageously
facilitate the locating of the single body 2, which is fixed by the
screwing of the bolts 12 into the threaded holes 11 in the front
surface 10 of the bearing 3.
During or after the positioning of the single body 2 on the bearing
3, the tubular portion 13 is inserted, again along the axis S, in
the central opening of the braking band 25 in which the first set
of teeth 26 in the bell region 24 engage the second set of teeth 27
of the braking band 25, achieving a form coupling which prevents
their relative rotation about the axis S.
The braking band 25 is slid along the tubular portion 13, towards
the connection flange 14, until a restraining ring 32 fixed firmly
to or integral with a side of the braking band 25 comes into
contact with the inner abutment surface 28 of the set of teeth 26
of the bell 24.
The individual pieces 33a, 33b of the keeper ring 33 are then
placed against the outer abutment surfaces 30, 31 of the engaged
sets of teeth 26, 27, from the exterior of the vehicle, and are
connected to the braking band 25 by screws 34 in order to restrain
the braking band axially in the bell region 24 of the single body
2.
The wheel-support unit 1 for vehicles with disk brakes according to
the invention has many advantages.
In the first place, it enables worn braking bands to be replaced
without any operation on the bearing and with the use of one-piece
braking bands rather than the sectional braking bands of the prior
art, resulting in low and uniform wear of the pads as well as a
reduction in costs in comparison with braking bands of the prior
art.
The present invention also enables the various components to be
optimized independently of one another, both with regard to the
construction material and with regard to their geometrical shapes.
For example, the structural separation of the braking band from the
bell enables the bell itself, that is, the single body, to be made
of a more expensive and stronger material than the material of the
braking band. The thickness of the single body can consequently
also be limited in comparison with that of the bell of the prior
art, achieving a reduction in weight and hence a saving in
material.
The bolts 12 which connect the single body to the bearing are not
stressed further during braking and the braking torque is
transmitted directly to the connection flange 14.
The wheel-support unit 1 is very strong and has an optimal
distribution of forces when the vehicle is in operation and in
particular during heavy braking.
The operations to fit and replace the braking bands are quicker and
therefore cheaper than those of the prior art and fitting is
further facilitated by the shapes of the connecting portion 8 and
of the seat 20 of the single body 2.
Naturally, variations and/or additions may be applied to the
embodiment described and illustrated, without departing from the
scope of the invention.
For example, the connecting portion 8 and the seat 20 may have one
or more complementary surfaces 10, 19, 22 for achieving a form
coupling between the outer ring 5 of the bearing 3 and the single
body 2.
According to one embodiment, this form coupling can prevent or
limit a relative translational movement between the outer ring 5 of
the bearing 3 and the single body 2 in a direction substantially
perpendicular to the axis S.
According to this embodiment, the form coupling also prevents or
limits relative rotational movement about the axis S between the
outer ring 5 of the bearing 3 and the single body 2.
According to an alternative embodiment, the bearing 3 has a
substantially cylindrical overall shape which enables the single
body 2 to be fitted on the bearing 3 in any angular position during
mounting.
Naturally, in order to satisfy contingent and specific
requirements, a person skilled in the art may apply to the
wheel-support unit for vehicles with disk brakes according to the
present invention further modifications and variations all of
which, however, are included within the scope of protection of the
invention as defined by the appended claims.
* * * * *